Mother Wasp II

Think wasp is a stinging machine? Think again.

If you’re a curious naturalist, and are amazed by little natural, but seemingly supernatural, feats all non-humans are capable of, be it your pet dog, cat, the wild tiger, or your unknown companion the ant, you are bound to have understood how closely related we all are albeit the fact that we’ve classified ourselves and made them appear quite distant from us. One of the startlingly familiar features common through almost all, if not the entire, Animal (or Plant) Kingdom, is motherly care. Mother was chosen to be the most beautiful word in English, and indeed it is, for it has a profound meaning incomparable to any – and by this I mean it is universal in (almost) all life.

I talked with much enthusiasm in 2010 about a mother wasp I had the fortune to be amazed by. It was an Ammophila wasp (Digger wasp), I had documented in the October heat of 2008, absorbed in ensuring that her offspring received plenty food and protection from outside elements. Now, as then, I met with another mother wasp absorbed in the same manner on an October day (the 12th), and I’m going to reiterate the story here. The catch is in how different yet similar both these distantly-related wasps are.

Before we begin, it is worth considering the season in which these wasps were seen nesting. October, the month following monsoon, sees a distinct rise in flowering of plants – and that means a surplus of food. Insects relying directly on flowers for their nectar and pollen, especially bees and wasps, beetles and butterflies, see a momentary peak in their numbers and diversity. Indeed, predators preying on these, like ants and spiders, also see an increase in their numbers. The best example is of the Giant Wood Spider whose females build elaborate orb-shaped webs high in the tree canopy in forests across India.

The twist in this seemingly linear flow of energy from herbivore to carnivore is rather humorous, for the herbivores also hunt the carnivores, as did our mother wasp, who is strictly vegetarian relying on pollen for survival, to secure a (strictly carnivorous) prey for her unborn offspring.

October precedes the cold and dry months of November, where plant activity begins to reduce, waterholes start to shrink, and the insect diversity slowly decreases. This month therefore, how-much-ever people in India hate for its oppressive weather, allergies to pollen, and humidity, is a bounty for the insects before the long break of the next wet season. In October, you will find the activities of mating and laying eggs – of making sure the progenies survive – is strife with competition, but is as mellow as a mother’s love. I hope our mother wasp distills the common perception of insects as senseless beings and throws some light on their amazing life.
A paralyzed Giant Wood Spider (Nephila pilipes)
4:15:26 PM
[Note: time given in the image is the time when the photograph was taken. It may not coincide with the time given in the text, for that time was recorded separately, however it falls in the time periods mentioned here.]

On a walk along the edge of the Central Indian forest, I happened across a dead Giant Wood Spider (Nephila pilipes). The time was approximately 4:05 PM. The sun was low in the sky, a few clouds hung in the east, and the air was still. A few inches from the nest was a burrow and some dug-up soil. After a moment, a wasp, golden-headed, bronze-winged, black bodied, stilt-legged, and stern of intentions as a Spartan, emerged, abdomen-first, with soil stuck to her mandibles, excavating and making the burrow deeper as the spider lay paralysed. She was a Spider Wasp in the family Pompilidae, a specialist in hunting spiders.
A Spider Wasp in the family Pompilidae digging a burrow
4:07:07 PM
Her narrow waist, intense eyes, an abdomen tapering down to a sting, should warn you she’s a wasp capable of a painful sting. But that’s not her only intention – in fact, that happens to be her last intention in life – her main intentions are feeding on flowers (thereby unknowingly pollinating), founding for a new life with a handsome male wasp perched atop a shrub, and then finding a suitable place to nest and a suitable prey of a suitable size, (for simplicity, I call it 3F’s of a spider wasp’s life prior to 3D’s). This is followed by getting down to digging, dragging, and drowning (3D’s of a spider wasp’s post 3F life). We don’t know how much effort that takes, for we've never been hunting with a knife attached to our behind.
...investigating the paralyzed spider.
4:07:13 PM
We can only imagine how she completed the 3F’s of her life – I’m sure it was not easy, what with ferocious birds flying around which would welcomingly kill her if they knew how to tackle her sting. And there were spider-webs, which, whether for irony or co-incidence, also happen to be the weapon of the spiders, her prey.
...making the burrow deeper
4:13:27 PM
When I saw her, she was already in the Digging stage of her life.

She removed the soil using her forelimbs, and probably her mandibles, and after every 3 to 5 to 11 minutes, she went and checked on her prey lying still. How did she find her prey, the Giant Wood Spider, is interesting. They are known to build some of the strongest webs in the world, are pretty huge considering their habit of hanging in their golden orb-webs from trees, and are also aggressive. Maneuvering to sting this hanging spider is also truly spectacular, unless she somehow managed to knock off the spider to the ground and then get the good of it.

When I came upon the Digging scene, most of the burrow was already dug. The hole was exactly the size to fit the spider into. It made me wonder if she inherently made the burrow of that size, or could she measure the spider to make the burrow. It further begs the question about the time she killed the spider: did she kill the spider after or before making the burrow?

Since the time I saw her at 4:05 until 5:05, she was digging, probably making the burrow longer if not wider. That’s 60 minutes of non-stop digging using only her feet and her mandibles.
...a mother warning a potentially threatening Carpenter Ant
4:18:11 PM
When she came across a Carpenter Ant (Camponotus compressus), sheS flung her forelimbs in the air, curved her abdomen, and warned the intruder of the grave mistake she’d commit. The ant opened her mandibles but decided to take a detour. On another occasion, she chased a dragonfly when it flew by too close. And on another, she whizzed by me for making sudden movements.

[Note: For photographing such a subject, one has to be extremely cautious and slow of movements – not because of the threat of getting stung, but because of the fear that the subject might feel threatened and abandon the activity which can even cost its or its unborn offspring’s life. I had no option then than to crouch and lay still.]
...using her mandibles to clear the dirt
4:20:31 PM
The sun was streaking far in the west, the shadows were lengthening, and the air was cooling down. The ground was wet from previous night’s rain. And our wasp was face-deep in the soil making a burrow of the exact shape and size which her mother, and her mother’s mother, and so on until you go back thousands, probably a million years, once did. Some scientists say that a wasp’s hunting skills improve with experience; in other words they refine their skills of the 3F’s and 3D’s – which also means that they undergo these stages multiple times in their lives.
A habitat shot showing the wasp on her burrow and the paralyzed spider along the edge of trees
4:28:28 PM
Spider wasps particularly target only spiders. I am not sure whether a species would target multiple species in her lifetime, for that will involve different strategies. Wasps known as Tarantula Wasp particularly hunts tarantulas of a particular genus only. Several spider wasps in India, whose taxonomic tangle is best left to be resolved by the taxonomists, also hunt Huntsman Spiders, Wolf Spiders, and Orb-weavers such as Neoscona sp. All except the latter dwell on ground. I came across a Spider Wasp hunting a Giant Wood Spider for the first time. Unfortunately I could not find any published record of the same. But to be able to do this, as I mentioned before, is quite remarkable.

The two scenarios of the wasp stinging the spider in the web, or after dropping it to the ground, are both quite distinct compared to wasps which hunt ground spiders. Could a wasp preferring ground spiders do this? Or did this wasp only hunt orb-weaving spiders, or in particular only the Giant Woods? Furthermore, how did she manage to fly with this heavy prey to the burrow? And while I was stuck at that thought (and still am), the wasp changed to Dragging stage of her life.

Remember I told you she checked on her prey every once in a while? Every time she did it, I thought we were at the Dragging stage, but this stage in real took approximately 60 minutes, and lasted only for 3 minutes.
...dragging the spider to the burrow
5:05:32 PM
She kept the spider beside the burrow, and went in to investigate, probably for the last touch-up. This stage, only lasting for about 20 seconds, is very important amongst all burrowing wasps.
...a typical behaviour of all burrowing wasps where they keep the prey outside and go in to investigate one last time.
5:05:45 PM
I’ve mentioned this behaviour in the previous post as well. Observed and elaborated first by Daniel Dennett, he showed that if, once the wasp goes in to inspect the burrow, the prey is moved to a distance – the wasp will come out, seek out the prey, lay it beside the nest, and go back in to investigate. Every time you do this, the wasp does the same. He termed it “antisphexishness”, after the wasps in the family Sphecidae in which he observed this behaviour, calling it “how seemingly thoughtful behaviour can actually be quiet mindless, this is opposite of freewill”. I decided against making the same observation in Spider Wasps, and let her go about her business.
...taking the spider to its grave
5:06:06 PM
She then came out, maneuvered herself so that she could pull the spider abdomen-first, entered the burrow abdomen-first, and dragged it in.
...she seemed to have got stuck for a few seconds while pulling the spider
5:06:30 PM
She seemed to have got stuck while dragging the spider in, probably because of the long limbs of the spider, but she pulled a bit further and then disappeared.
...emerging from the burrow after securing the spider, and probably laying an egg
5:07:53 PM
In about 20 seconds, I saw her clearing the entrance to the burrow of roots and soil as she came back up. And here we come to the end of the Dragging stage and enter the Drowning stage (Drowning in context of this article means burring of the paralyzed spider).
...burying the entrance
5:12:34 PM
As soon as she emerged, she tossed some soil over the burrow using her forelimbs, and covered it to the rim. She did this for about 2 minutes, and then, using her abdomen as, literally, a hammer, she hammered the soil down until it was firm enough.
...using the tip of her abdomen to pack the soil into the burrow
5:16:27 PM
This behaviour is another revelation to me – for that end is not only a powerful stinger, but also an ovipositor (from where an egg is laid). Using it as a hammer, and with a speed I cannot fathom, she made sure that the soil over the burrow was packed well to keep the egg safe.
...catapulting the soil particles away from the burrow
5:32:18 PM
After filling the soil, she started flinging the leftover soil away from the nest. She did so quite efficiently using her fore- and hind-limbs as anchor, and using her middle appendages as a catapult.
A portrait of the mother and her nest as she cleared the remaining soil from the site
5:39:49 PM
She made sure that the extra soil was two inches away from the burrow, and then proceeded to remove the roots and other material from the site.
...clearing the bits and pieces of roots from the nest site
5:43:03 PM
She gave the final touch to the burrow at approximately 5:58 PM.
...a safe sanctuary to the unborn wasp
5:58:38 PM
With the final stage at its end, and with the wasp now satisfied that the burrow was perfectly covered to resemble the nearby ground, she flew off, rested on a shrub for a few seconds, and vanished in the cool of the twilight.

The drowning stage took 50 minutes (digging took 60 minutes and dragging 3 minutes), and the overall time taken for the 3D’s was 113 minutes (1.53 hours). We can only imagine how long the 3F’s took, but it is fair to assume that this wasp has been on the run for most of her life, from the day she emerged from a very similar borrow – dazed, energetic if not expectant or hopeful, and definitely dedicated to her life.

What amazes me is not the fact that her genes were so perfectly modeled by natural selection to give her this life. Some call it mechanical and mindless, but it is nothing but the simplest, and the one that gives the best output not only in terms of passing on her progeny, but a willful service to nature.

If I begin to count the efforts of this one wasp in monetary terms, her salary, for her size, is far too rich than that of you and I. In today’s times, without making a monetary comparison, it is impossible to deduce the value of any living being, whether man or an animal. Although this is highly unfortunate, it happens to be the only way many of us understand the true value of nature: from a small mother wasp to the large bull elephant.

In this remarkable feat achieved by this wasp, rather one of the many remarkable feats, she reminds me of a very simple emotion we mostly associate with human life. In saying so, I am personifying the wasp as a man, but that is only because we’re related – if not in the way we classify organisms – certainly in the way of a mother.

No comments:

Post a Comment